Fluid-fuel-burner control



March 26,, 1-929. P. F. SHIVERS 4 FLUID FUEL BURNER CONTROL Filed May 1927 2 Sheets-Sheet 1 m m E m f E m WE WA 1 Y a B March 26, 1929. P. F. sHlvERs FLUID FUEL BURNER CONTROL 2 Sheets-Sheet 2 Filed May '7, 1927 INVENTOB fall! ES/zwera,

ATTORNEYS Patented Mar. 26, 1929.

UNITED STATES PATENT oFFicE.

PAUL F. SHIVERS, OF WABASH, INDIANA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNIE SOTA, A CORPORATION OF DELAWARE.

FLUID-FUEL-BURNER CONTROL.

Application filed May 7,1927. Serial No. 189,478.

The object of my invention is to provide a simple and eflicient means for automatically controlling the action of a fluid-fuel burner so that it may be depended upon to permit automatic normal operations of the burner but will prevent delivery of fuel in all cases of accidental failure of ignition or combustion.

The accompanying drawings illustrate my invention diagrammatically, Fig. 1 showing one form of interlock switch, and Fig: 2' showing another. Flow of current from the main power leads 10 and 11 is controlled by a room thermostat T of any desired type capable of properly controlling the current. Other. associatedcontrol mechanism, such for instance as a boiler control 13 or pressure control may be coupled in at this point. Wire 12 connects lead 11 with T.

Leading from the thermostat T is-wire 14 which connects to the bi-metallic thermostatic blade 15 of the warp switch W. Elecof the heating coil 16 connected by wire 17 to a terminal 18 of the combustion-control C.

The combustion-control C is a circuit determining element sensitive to combustion conditions closely adjacent the burner and 30 may conveniently be a well-known thermostatic device which, while movable through a wide range, serves to change circuits promptly upon rise or fall of temperature.

Paired with terminal 18 is a terminal19 connected by wire 20 with blade 15 and by wire 21 with terminal 22 of the interlocking switch L. Paired with terminal 22 is a terminal 23 connected by wire 24 with the tongue 25 of the warp switch W, said tongue being insulated from blade15 and normally held by blade 15 in contact with terminal 26 against the bias of spring 27.

Terminal 26 is connected by wire 28 with the stator 29 of an oil valve motor VM, the opposite end of said stator being connected by wire 30 with the main lead 10. 1

Wire 24 also leads to the terminal 31 in th combustion-control C, said terminal being trically connected to the blade 15 is one end associated with terminals 32 and 33. Ter minal 33 is electrically connected with terminal 19 and wire 20. A globule of mercury 39 may electrically connect terminals 313233 or terminals 18-19.

' Terminal 32 is connected by wire 34 with the electric. ignition mechanism I which, in the present instance includes the spark mechanism 35 and the elctrically controlled pilotgas-valve 36, the elements of the ignition mechanism being connected by wire 37 with the main lead 10. This ignition mechanism is well known and needs no further illustra tion.

Terminals 22 and 23 form part of a switch mechanism which, in Fig. 1 is a mercury tube having the mercury 40 which is normally away from terminals 22 and 23, i. e., when the oil valve is closed.

7 Terminal 18 is connected by wire 14 to a terminal 45 of a fuel motor switch S and the terminal is paired with a terminal 46' -in a mercury tube 47, the circuit at terminals 45 and 46 being normally open. Terminal 4.6 is connected by wire 18 with one side of the fuel motor M, the other side of said fuel motor being connected by wire 4:9with wire v2'5 30 and one end of the stator 29.

The rotor of the valve motor VM is connected by a train of reducing gears 50 with a reciprocable plunger 52 of an oil valve 53 which controls flow of fuel to the burner. Val-ve 53 is normally closed by a spring'54: which biases the plunger to closed position against the action of the 'valve motor. The details of construction of this valve form the subject matterof my co-pending application Serial No. 111.154. In Fig. 1 the two switches S and L are carried by a pivoted carrier 55 pivoted at 56 and connected at 57 to plunger 52, the arrangement being such that terminals 454:6 and 2223 are elec- 9o trically connected only when the valve is open.

In Fig. 2 the construction and arrangement are the same except that instead of the mercury tube L, I provide a terminal 22 5 biased to open position by spring 60 and engaged by plunger 52 against the bias of the spring. Terminal 22 is brought into contact with terminal 23 by the opening movement of the oil valve.

Terminal 22 is electrically connected with blade and terminals 19 and 33 while terminal 23 is electrically connected With terminal 31 and leaf 25.

The operation is as follows:

The diagram shows the parts in the positions occupied when there is no call for heat.

When heat is-called for the room thermostat or its equivalent, will close the circuit 1112142033-32-34-13710 to produce ignition for fuel to be delivered at the burner. It also closes the circuit 11 1214 -20-3331252628 and the stator 29 of the oil valve motor VM, thus starting the oil valve motor in opening direction against the bias of the return spring 54 which acts on plunger 52. This swings the interlock switch L and motor switch S.

Shifting switch S closes the circuit 11- 121415161744454648M 493010 and starts motor M to deliver fuel to the burner, the oil valve 52 being already open. Shifting switch L closes the circuit 1l-l21420-212223 (22-23' in Fig. 2) 2-1252628293010 thus providing a maintaining circuit for the fuel valve motor upon break of the circuit through 33-31 when the combustion control is heated.

The circuit through the motor M includes the heating coil 16 of the warp switch W so that if there is no ignition and consequent heating of the combustion control or if, at any time there is a failure of combustion and a return of control C to cold position, the Warp switch will be heated so as to cause a break between and 26 thus breaking the valve motor circuit and permitting the spring 54 to return plunger 52 to its normal position, thereby breaking the circuit of motor M at 46. Switch W must then be reset by hand.

In normal operation a break at the room thermostat, due to suflicient heating of the adjacent space, breaks the circuit of the fuel valve motor VM and fuel motor M and permils the parts to return to cold position.

' \Vhile I have illustrated mercury tube switches at various points it will be readily understood that any desired form of circuit breaker suitable for handling the necessary current may be. substituted without departing from my invention. It will also be understood that the details of motor VM and its connection with the switches actuated thereby may be considerably modified and that it is not absolutely essential that this motor actuates a fuel valve because, while such a valve is quite desirable to insure against leakage of fuel past the fuel delivering apparatus driven or controlled by motor M, such apparatus controlled by motor M may be solely relied upon to control the flow of fuel. For convenience motor M may be called the fuel motor and motor VM may be called the supplemental motor. The details of the warp switch may be varied, the essential characteristic being that there be a retarded circuit-breaking action after a predetermined time interval of current flow in the absence of combusiton at the burner, and the term warp switch in the claims is used to designate such a device generally, and the term heating coil is used to designate generally the element thereof electrically causing circuit-breaking action.

The fuel motor may driveor control a fuel pump or other fuel-flow control means and may drive movable parts of the burner proper.

The term room thermostat is used to designate a remote circuit-controlling element sensitive to thermal or other conditions to be affected by the burner.

These various details may be varied through a wide range without departing from my invention.

I claim as my invention:

1. In a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor and comprising a circuit breaker and the heating coil of a warp switch, a supplemental motor, an energizing circuit for said supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner,

a maintaining circuit for the supplemental motor comprising the warp switch and a circuit breaker subject to action of the supplemental motor, means actuated by the supplemental motor for shifting the circuit breakers of the fuel motor circuit and the supplemental motor maintaining circuit, and a circuit breaker subject to combustion conditions adjacent the burner and arranged to shunt the heating coil during combustion.

2. In a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor and comprising a circuit breaker and the heating coil of a warp switch, a fuel valve, a supplemental motor for opening said fuel valve, an energizing circuit for said supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner, a maintaining circuit for the supplemental motor comprising the warp switch and a circuit breaker subject to action of the supplemental motor, means actuated by the supplemental motor for shifting the circuit breakers of the fuel motor circuit and the supplemental motor maintaining circuit and a circuit breaker subject to combustion conditions adjacent the burner and arranged to shunt the heating coil during combustion.

3. in a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor comprising a circuit breaker and the heating coil of a warp switch, a supplemental motor, an energizing circuit for said supplemental motor comprising the warp switch and a circuit breaker sub ect to combustion conditions adjacent the b'urner,1a

tor maintaining circuit, an electric ignition T means and an energizing circuit for said ignition means comprising a circuit bi eaker subject to combustion conditions adjacent the burner, and a circuit breaker subject to combustion conditions adjacent'the burner and arranged to shunt the heating coil during combustion.

4. In a control system for fluid fuel burners, a fuel motor, an energizing circuitfor said fuel motor comprising a circuitfbreaker and the heating coil of a warp switch, a fuel valve, a supplemental motor for opening said fuel valve,-- an energizing clrcuit for said supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner, a-

maintaining circuit for the supplemental motor comprising the warp switch and a cir cult breaker subject to action of the supplemental motor, means actuated by the supplemental motor for shifting the circuit breakers of the fuel motor circuit and the supplemental motor maintaining circuit, an electric ignition means and an energizing circuit for said ignition means comprising a circuit breaker subject to combustion conditions adjacent the burner, and a circuit. breaker subject to combustion conditions adjacent the burner and arranged to shunt the heating coil during combustion. V

5. In a control system for fluid fuel burners, afuel motor, an energizing circuit for said fuel motor comprising a circuit breaker and the heating coil of a warp switch, a supple-' mental motor, a reciprocable elementactuated by said supplemental motor in one direction,

means for biasing said reciprocable element against the action of the supplemental motor, an energizing circuit for said supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner, a maintaining circuit for the supplemental motor comprising the warp switch and a circuit breaker subject to action of the reciprocable element, means actuated by the supplemental motor for shifting thB ClPCIJ1t breakers of the fuel motorv circuit and the supplemental motor maintaming circuit,v and a circuit breaker sub- "ect to combustion conditions adjacent the urner: and arranged to shunt the heating coll durmg combustion.

6. .In a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor comprising a circuitbreaker and the heating coil of a warp switch, a fuel Valve,

a supplemental motor, a reciprocable element actuated by said supplemental motor in one direction and controlling said valve, means for biasing said reciprocable'element against the action of the supplemental motor, an energizing circuit for and supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner, a maintaining circuit for the supplemental motor comprising, the warp switch and a circuit breaker subject to action of the'reciprocable element, means actuated by the supplemental motor for shifting the circuit breakers of the fuel motor circuit and the supplemental motor maintaining circuit, and a circuit breaker subject to combustion conditions adjacent the burner and arranged to shunt the heating coil during combustion.

7 In a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor comprising a circuit breaker and the heating coil of a warp switch, a supplemental motor, a reciprocable element actu ated by said supplemental motor in one direction, means for biasing said reciprocable element against the action of the supplemental motor, an energizing circuit for said supplemental motor comprising the warp switch and a circuit breaker subject to combustion conditions adjacent the burner, a maintaining circuit for the supplemental motor comprising the warp, switch and a circuit breaker subject to action of the reciprocable element, means actuated by the supplemental motor for shifting the circuit breakers of the fuel motor circuit and the supplemental motor maintaining circuit, an electric ignition means and an energizing circuit for said ignition means and comprising a circuit breaker subject to combustion conditions adjacent the burner, and a circuit breaker subject to combustion conditions adjacent the burner and arranged to shunt the heating coil during combustion.

v8. In a control system for fluid fuel burners, a fuel motor, an energizing circuit for said fuel motor comprising a circuit breaker and the heating coil of a warp switch, a fuel valve, a supplemental motor, a reciprocable element actuated by said supplemental motor in one direction and controlling said valve, means for biasing saidreciprocable element against the action of the supplemental motor, an

energizing circuit for said supplemental motor comprising the warp switch and acircuit breaker subject to combustion conditions adjacent'the burner, -a maintaining circuit for the supplemental motor comprising the warp switch and a circuit breaker subject to action of the reciprocable element, means ditions adjacent the burner and arranged to shunt the heating coil during combustion.

In witness whereof, I, PAUL F. SHIvERs, have hereunto set my hand at Wabash, Indiana, this 30th dayof April, A D. one thousand nine hundred and twenty seven.

PAUL F. snivnns. 

